Starting with the Cleveland Barons in 2005, then the American Hockey League affiliate of the San Jose Sharks, the 33-year-old — born in Brockton and raised in Rockland — had an additional stop in Ottawa and their AHL affiliate formerly in Binghamton, before spending the 2010-11 season in Switzerland.
Hennessy returned to North America for his hometown Boston Bruins the following season. He dressed in 69 contests for Providence, scoring 19 goals and 22 assists for 41 points, while also appearing in three games for the big club.
From 2012-17, Hennessy bounced around from the Kontinental Hockey League in Russia, then back to the Swiss National League and back to the KHL once more before ultimately finishing his second tour of Europe in the Swedish Elite League.